The Labour Party held Erith and Thamesmead to ensure a hung parliament. at 9.45 this morning.

David Cameron held out a “big, open and comprehensive offer” to the Liberal Democrats to work together in government.

In a statement in Westminster, he acknowledged that there would have to be reform of the electoral system and he proposed the creation of an all-party committee of inquiry to look at the issue.

Liberal Democrat leader Nick Clegg will offer the Conservative Party “first right” to attempt to form a government in the “national interest”.

Mr Clegg said it was now for the Tories to prove themselves capable.

He added: “I have said that whichever party gets the most votes and the most seats has the first right to seek to govern, either on its own or by reaching out to other parties and I stick to that view.

“I think it is now for the Conservative Party to prove that it is capable of seeking to govern in the national interest.”

A deflated Gordon Brown later announced that he is willing to see any of the party leaders if David Cameron and Clegg do not reach an agreement on forming a government.

Cameron said: “What’s clear from these results is that the country, our country, wants change. That change is going to require new leadership and we will stand ready to do all we can to help bring that leadership.”

A rollercoaster night may not have produced a clear result, but it did deliver some memorable moments, including the defeat of some of Westminster’s big names.

High-profile casualties at the ballot box were former home secretary Jacqui Smith - who was an early casualty of the MPs’ expenses scandal - ex-Cabinet heavyweight Charles Clarke and a clutch of junior ministers.

But Tories were denied their “Portillo moment” in Morley and Outwood, where Mr Brown’s closest Cabinet ally - and possible successor - Ed Balls hung on with a majority of just over 1,000 despite a determined Conservative effort to “decapitate” him.

A handful of prominent Lib Dems lost their seats included Lembit Opik, ousted by a massive swing to the Conservatives in Montgomeryshire, and Susan Kramer, who lost to environmentalist millionaire Tory Zac Goldsmith in Richmond Park.

And in Northern Ireland, Democratic Unionist leader Peter Robinson - damaged by recent revelations about his wife’s private life - sensationally lost his East Belfast seat to the city’s lord mayor Naomi Long, who becomes the non-sectarian Alliance Party’s first MP.

In Brighton Pavilion, Green leader Caroline Lucas became her party’s first MP, telling cheering supporters that they had put “the politics of hope above the politics of fear”.

But the British National Party failed to deliver the breakthrough it was hoping for, with leader Nick Griffin trailing in third place in Barking. Labour victor Margaret Hodge said voters in the east London seat had sent a clear message to the extreme-right party: “Pack your bags and go.”

As he won his seat in Witney, Oxfordshire, Cameron said: “I believe it is already clear that the Labour Government has lost its mandate to govern our country.

“Although there are still many more results to come out, it looks as if the Conservative party is on target to win more seats than we have done at any election for perhaps as long as 80 years.

“Whatever happens tonight we will stand ready to do all that we can to help bring that leadership, to help bring strong, stable, decisive and good government for our country.

“What will guide me in the hours ahead, and perhaps longer than the hours ahead, will be the national interest – to do what is right for our country, to make sure we have that government, have that stability, take the right decisions."

The big shock of the night was the chaos at polling stations across the country, with thousands denied the chance to cast their votes.

Huge queues formed in constituencies including Birmingham Ladywood, Sheffield Hallam, Manchester Withington, Lewisham in south London, and Chester, with angry crowds ­being turned away still clutching their polling cards.

Problems were also reported in Newcastle, Leeds and Milton Keynes.

Police were called after voters in Hackney, east London, staged a sit-in demanding their democratic right.

Polling stations in Liverpool Wavertree even ran out of ballot papers.

Jenny Watson, chairwoman of the Electoral Commission, said the current system was “at breaking point” and the law might need to be changed as a result.

Asked if Labour would seek a deal with Clegg, he said: “I have no problem in principle in trying to supply this country with a strong and stable government.”

Brown himself dropped a hint that he would not quit without a fight in his speech after holding Kirkcaldy and Cowdenbeath.

He said: “The outcome of this country’s vote is not yet known, but my duty to the country, coming out of this election, is to play my part in Britain having a strong, stable and principled government, able to lead Britain into sustained economic recovery.”

“We live in difficult times but this is a great country and we will come through them and be stronger.”

Ex-Home Secretary David Blunkett was the most senior Labour figure to stick his neck out and say Brown had “lost” the election.